As cutting tools having a cutting edge made of sintered diamond particles or sintered cubic boron nitride (cBN) particles, a reamer disclosed in Japanese Patent Laying-Open No. 2000-263328 (Patent Document 1) and a cutting tool disclosed in Japanese Patent Laying-Open No. 3-10707 (Patent Document 2), for example, have been known.
The reamer disclosed in Patent Document 1 includes a shank, a radial blade portion, and a cutting edge body. The radial blade portion extends from the shank. The shank and the radial blade portion are made of cemented carbide or steel. To the top end of the radial blade portion, the cutting edge body is joined. The cutting edge body is made of sintered diamond or cubic boron nitride particles. Flute blades and flutes are formed on the outer peripheries of the radial blade portion and the cutting edge body. The flute blades and flutes are formed helically about the central axis. Each flute is located between adjacent flute blades.
The cutting tool disclosed in Patent Document 2 includes a tool body and a cutting edge insert. The cutting edge insert is secured to the tool body. The cutting edge insert is made of sintered diamond particles, sintered high pressure phase boron nitride particles, or a sintered mixture of them.